"H. Peter Anvin" <hpa at zytor.com> writes: > On 07/29/2010 12:55 PM, Randy Dunlap wrote: >>> >>> And device_shutdown calls every drivers .shutdown method. >>> >>> Things like this are always a driver problem. >> >> so is there a default .shutdown method for drivers that do not specify one? >> >> like the qla2xxx driver does not. >> > > If it doesn't, even if bus mastering gets shut off at the core level, > there is a risk that is clobbers data when it turns it back on if the > initialization sequence is problematic. There isn't a bus master shut off at the core level. When we did the original analysis it turned out that the bus mastering bit was implemented on a lot of devices in advisory way, so it didn't make sense to count on it. That said it looks like the code to do the shutdown is in qla2x00_remove_one so it should be too hard if someone cared to extract just the hardware bits. Eric
